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Shaders: Make Mesh partly visible with Shadows
Hi
I am using a Shader to cut all Meshes above a specific Y level. This is working but the Shadows that are generated are wrong. How i can correct this? The left picture shows the problem and in the right picture there is nothing cuttet. (U can Ignore the trees)
Here is my Shader:
Shader "Test/Rim Shading Multiple Lights Texture Shadows" {
Properties{
_Color ("Color",Color) = (1.0,1.0,1.0,1.0)
_MainTex("Diffuse Texture",2D) = "white"{}
_SpecColor("SpecColor",Color) = (1.0,1.0,1.0,1.0)
_Shininess("Shininess",Float) = 10
_RimColor ("Rim Color", Color) = (1.0,1.0,1.0,1.0)
_RimPower("Rim Power",Range (0.1,10.0)) = 3.0
_LastVisibleY("LastVisibleY", Float) = 50.0
}
SubShader {
Pass{
Tags{"LightMode" = "ForwardBase"}
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#pragma multi_compile_fwdbase
#include "AutoLight.cginc"
//user defined Variable
uniform sampler2D _MainTex;
uniform float4 _MainTex_ST;
uniform float4 _Color;
uniform float4 _SpecColor;
uniform float4 _RimColor;
uniform float _Shininess;
uniform float _RimPower;
uniform float _LastVisibleY;
//unity defined Variables
uniform float4 _LightColor0;
struct vertexInput{
float4 vertex : POSITION;
float3 normal : NORMAL;
float4 texcoord : TEXCOORD0;
};
struct vertexOutput{
float4 pos : SV_POSITION;
float4 tex : TEXCOORD0;
float4 posWorld : TEXCOORD1;
float3 normalDir : TEXCOORD2;
LIGHTING_COORDS(3,4)
};
vertexOutput vert(vertexInput v)
{
vertexOutput o;
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
o.posWorld = mul(_Object2World, v.vertex);
o.normalDir = normalize(mul(float4(v.normal,0.0),_World2Object).xyz);
o.tex = v.texcoord;
TRANSFER_VERTEX_TO_FRAGMENT(o);
return o;
}
float4 frag(vertexOutput i) : COLOR
{
if(i.posWorld.y > _LastVisibleY)
discard;
float3 normalDirection = i.normalDir;
float3 viewDirection = normalize(_WorldSpaceCameraPos.xyz - i.posWorld.xyz);
float3 lightDirection;
float atten;
if(_WorldSpaceLightPos0.w == 0.0)
{
atten = 1.0;
lightDirection = normalize(_WorldSpaceLightPos0.xyz);
}
else
{
float3 fragmentToLightSource = _WorldSpaceLightPos0.xyz - i.posWorld.xyz;
float distance = length(fragmentToLightSource);
atten = 1/distance;
lightDirection = normalize(fragmentToLightSource);
}
atten = atten * LIGHT_ATTENUATION(i);
//lighting
float3 diffuseReflection = atten * _LightColor0.xyz * saturate(dot(normalDirection, lightDirection));
float3 specularReflection =atten * _LightColor0.xyz * _SpecColor.rgb * saturate(dot(normalDirection, lightDirection)) *pow( saturate(dot(reflect(-lightDirection,normalDirection),viewDirection)),_Shininess);
//Rim Lighting
float rim = 1 - saturate(dot(normalize(viewDirection),normalDirection));
float3 rimLighting = atten * _LightColor0.xyz * _RimColor * saturate(dot(normalDirection, lightDirection)) * pow(rim,_RimPower);
float3 lightFinal = rimLighting + diffuseReflection + specularReflection + UNITY_LIGHTMODEL_AMBIENT.xyz;;
//float atten2 = LIGHT_ATTENUATION(i)* atten;
//Texture
float4 tex = tex2D(_MainTex,i.tex.xy * _MainTex_ST.xy + _MainTex_ST.zw);
return float4(tex.xyz * lightFinal * _Color,1.0);
}
ENDCG
}
}
FallBack "VertexLit"
}
shadow.png
(221.9 kB)
Comment
Best Answer
Answer by Rabbito · Jun 07, 2015 at 09:47 AM
I have made it by adding the Shadowcaster Pass into the Shader:
// Pass to render object as a shadow caster
Pass {
Name "ShadowCaster"
Tags { "LightMode" = "ShadowCaster" }
Fog {Mode Off}
ZWrite On ZTest Less Cull Off
Offset 1, 1
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma multi_compile_shadowcaster
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"
uniform float _LastVisibleY;
struct v2f {
V2F_SHADOW_CASTER;
float4 posWorld : TEXCOORD1;
};
v2f vert( appdata_base v )
{
v2f o;
o.posWorld = mul(_Object2World, v.vertex);
// if(o.posWorld.y < _LastVisibleY)
// {
TRANSFER_SHADOW_CASTER(o)
// }
return o;
}
float4 frag( v2f i ) : COLOR
{
if(i.posWorld.y > _LastVisibleY)
{
discard;
}
SHADOW_CASTER_FRAGMENT(i)
}
ENDCG
}